A Clinical Investigation Core is an essential component of a multi- disciplinary HIV research program which fosters translational research through collaboration between clinical and basic scientists. Observations made in the basic science laboratory may merit validation and hypothesis may warrant testing with well characterized clinical specimens from HIV- infected patients. Diagnostic assays which are often developed from laboratory strains of organisms require evaluation with clinical isolates. Some translational research questions can be adequately addressed through analysis of stored specimens, but many require the prospective collection of fresh blood in select populations and specialized processing which is optimally coordinated and conducted by an experienced set of investigators and staff. The objective of the Clinical Investigation Core is to provide access of HIV patient specimens and clinical trials expertise to laboratory and clinical scientists studying HIV pathogenesis and associated opportunistic infections. A secondary objective of the Core is to provide access of specimens to investigators developing diagnostic assays for patient recruitment services including outreach to women, minorities and infection drug users, b) consultation on study design and analysis, c) acquisition of clinical specimens, and d) data entry and collection. The Clinical Investigation Core will promoter AIDS translational research by offering expert consultation by experiencing clinical investigators at an established HIV clinical research unit and access to participants in vaccine, anti-retroviral immune modulator, HIV primary infection, and opportunistic infection protocols. The Core will also permit the use of an established and experienced clinical research unit to obtain and distribute specimens for laboratory based research. The proposed Clinical Investigation Core will provide new opportunities for HIV investigators to study pathogenesis of HIV and associated infections.